All products featured on Wired are independently selected by our editors. However, we may receive compensation from retailers and/or from purchases of products through these links.
Virtual Private Networks, or VPNs, are now widely used to add extra security to online connections, to improve privacy when browsing, and to spoof location information—they can even be set up at the router level to protect every device on the network. And if you've got one installed, you need to be aware of one of their key features: the kill switch.
To begin with, it's important to bear in mind that a VPN doesn't make you anonymous online. If you log in to Amazon, Amazon will still keep track of what you're looking at and what you're buying. If you're signed in to Google and Chrome, your searches and online activity will get logged as normal.
However, with a VPN enabled, your devices don't connect directly to websites and servers. Instead, they establish encrypted connections to nodes set up by your VPN provider of choice, and you connect to your intended destinations from there: That means the sites you visit and the apps you use can't as easily pin down where you’re located and what devices you’re using.
It also makes it a lot harder for other people to see what you're doing online, whether it's a coffee shop Wi-Fi hacker, your internet provider, or a government agency. All they see is you connecting to the VPN you've chosen and not whatever you do after that. So the best VPNs won't make you anonymous, but they will make your browsing more private and secure.
What Is a VPN Kill Switch?
Now that we've established what a VPN is and what a VPN does, we can talk about the kill switch. Kill switches are necessary because VPN servers aren't infallible: They can and do go down, even with the best VPNs. Something unexpected might also happen at your end, breaking the connection you've established with your VPN provider.
Should something go wrong with your VPN server or your device, even if it's a temporary blip, that extra layer of privacy and security goes away in an instant. Your browsing and app use is then exposed—which is probably not something you want if you've taken the trouble to install a VPN to begin with.
A kill switch—as it does on machinery—shuts everything down. Your internet access will be automatically cut off when the VPN connection is lost: So while you'll have the inconvenience of suddenly being offline, you won't be sending and receiving data that other people are going to be able to get at.
Without a kill switch, the site or app you're connected to would suddenly have access to your IP address, for example, and from there perhaps your location and more information about you. The more serious your reasons for using a VPN—to avoid censorship restrictions, perhaps, or to protect sensitive information—the more important it becomes to have a kill switch in place.
How to Enable a VPN Kill Switch
How you make use of a kill switch will depend on the VPN provider you choose and the features available in the software you get. Some VPNs don't offer a kill switch, and those that do vary as to whether it's enabled by default. If this is definitely a feature you want to make use of, find a VPN service that offers it.
The feature should be somewhere in the settings of the VPN apps you're using on your computer, tablet, or phone—though you may have to dig into the advanced section of the settings to find it. In the case of the Proton VPN desktop app, for example, the kill switch button can be found on the Countries tab on the main dashboard.
If you use NordVPN on your computer, click the gear icon on the top toolbar, then choose Kill Switch from the list of options on the left. For ExpressVPN users with the desktop client installed, the kill switch can be found by clicking the menu button (top left), then Options and General: You can then check the box marked Stop all internet traffic if the VPN disconnects unexpectedly.
It's in different places for different VPN apps on different platforms—and it sometimes has different names—but the basic idea is the same. In addition, some VPNs offer a kill switch that gets activated only when you're using certain programs and apps, so it's not a blanket rule that applies to all internet access.
